Telnet is similar to HTTP and FTP in that all three use the TCP protocol for connection-oriented
DHCP is a connectionless protocols. In general, any protocol that is based on TCP port alone is a connection-oriented protocol while any protocol that is based on UDP port alone is a connectionless protocol. And a protocols that can work on both TCP and UDP port can be either a connection-oriented or a connectionless protocol depending upon the which protocol is used (TCP or UDP). For checking other protocols if they are connection-oriented or connectionless check http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
Different from a connectionless protocol, a connection-oriented protocol guaranties the delivery of the information. An example of connection-oriented protocol is (TCP) and a connectionless protocol is (UDP). TCP is a connection-oriented protocol, it makes a connection and checks whether the data is received, and resends if it is not. UDP is a connectionless protocol, it does not guarantee delivery by first connecting and checking whether data is received.
TCP is the protocol of network layer, It is connection oriented protocol. UDP is the protocol of network layer, It is connection less protocol.
Transmission Control Protocol (TCP) is used when data reliability is needed since it is connection oriented and guarantees delivery.
Email runs SMTP (simple mail transfer protocol), where SMTP operates over TCP protocol, so it id connection oriented.
Different from a connectionless protocol, a connection-oriented protocol guaranties the delivery of the information. An example of connection-oriented protocol is (TCP) and a connectionless protocol is (UDP). page/926 A+
Connection oriented is more reliable because there is an acknowledgment received from data receiver (destination) that the data is receiving and transfer is successful which is not received from connection less protocol.
Simple mail transfer protocol Incorrect it is TCP
Connection-oriented protocol
Layer 4 (Transport)
A reliable data transfer is one that is stable . For a reliable data transfer a connection oriented protocol is used. A connection oriented protocol is one that receives acknowledgement from the receiver before sending the further data.